*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19782
19790
19800
19810
19820
19830
19840
19850
19860
19870
19881
19890
19901
19910
19920
19930
19941
19950
19961
19970
19980
19990
20000
20011
20021
20030
20040
20050
20064
20070
20081
20090
20100
20110
20120
20130
20140
20150
20160
20170
Total13